Apcor, the Portugese Cork Association, is leading the Intercork campaign and has called for agency proposals covering a range of global markets.
The bulk of the enormous budget has been earmarked to promote cork as a wine bottle stopper in countries such as the UK, the US, France, Italy, and Germany.
The campaign will target consumers, the wine industry and the media in an attempt to combat a growing preference for screwcaps. It will highlight the biodiversity benefits of cork forests and the superior quality of cork compared with metal screwcaps.
The campaign also includes an element that will attempt to promote cork's use as a construction and decorative material. This part of the blitz will target such countries as China, the UAE, Germany, Russia and Japan.
Agencies this week submitted proposals for the tender, with Apcor expected to make its decision by January. An agency source involved in the process said a number of firms were likely to be involved, given that the tenders were being split by country.
Claudia Pimenta from Apcor's comms department said: 'Cork is facing issues, which is something we need to communicate.'
Pimenta said the association expected to make a decision 'by the beginning of January next year'.
Portugal is an important producer of cork, accounting for about 50 per cent of global production. Cork represents 70 per cent of the country's export trade. It has been estimated that 16 per cent of the country's foreign income comes from cork sales.
Apcor director Joaquim Lima said: 'Intercork is the biggest communication project that Apcor has ever developed.' He added that the project was an 'acknowledgement of the vital importance of the cork industry to our country'.